Tool-driver



L. s. STARRTT.

,TooL DRIVER. APPLICATION FILED DEC. I6,.I9I4.

Patented May 27, 1919.

2 SHEETS-SHEET l.

gnvzntor: LAROY 5. STARRETT.

f al' d 001 l Attorney.

Lr S. STARRETT.

Patented May 27, 1919.

2 SHEETS-SHEET 2.

TOOL DRIVER.

APPLICATION FILED DEC.16. 1914. 1,304,7140

ms NoRms Farms ce., mfom-umn.. wAsHuvc van:4 uv cv Inve ntor 1 LAROY 5. STARRETT.

By rv" l l* "l r/ Attorney.

UNITED sTATEs PATENT oEEioE.

LAROY S. STARRETT, 0F ATHOL, MASSACHUSETTS, ASSIGNOR T0 THE L. S.

STARRFTT COMPANY, A CORPORATION OF MASSACHUSETTS.

TOOL-DRIVER.

Specification of Letters Patent. Patented'May 27, 1919.

Application led December 16, 1914. Serial No. 877,586.

Athol, county of Worcester, Commonwealth of Massachusetts, have invented certain new and useful Improvements in Tool-Drivers,

of which the following is a specification.

This invention relates to wood and metal working tools and particularly to a spiral ratchet screw driver wherein the tool spindle is rotated about its axis by reciprocatory movements of thehandle.

an yordinary screw driver; or by a further shifting operation the spindle may be successfully operated in reverse direction. In order to adapt a tool 'having the above characteristics to the requirements of manufacture and use, it is primarily essential that both the ratchet mechanism and the adjusting mechanism for the various phases of operation shall be of such construction as to secure certainty of action and readiness of adjustment without Vundue complication of parts and without difliculties of manipula- To the end therefore of providing a tool 0f this type which will embody the features above pointed out and will avoid those features which areobjectionable, I have devised my present invention. YThe tool of my present invention carries as an additional feature of advantage the fact that the screw driver blade is positively held in the slot of the screw while the return motion of the handle is made. This is eected in the present invention by means of a coil spring normally under tension and released by a simple shifting operation at the time the tool spindle is rotated to drive the screw. The tend- 'ency of the spring is to prevent the "screw driver blade from being drawn out of the slot of the screw .when the handle is moved back to original position.

The construction and operation of my device will be more fully disclosed in the speciication following. In the drawingsforming a part of that specification I have Vshown as an illustrative embodiment, a form of tool driver which has been found satisfactory in use and welladapted to the requirements of manufacture.

Throughout specification and drawings 4like reference Anumerals are correspondingly applied, and in these drawings:

Figure 1 is a central' longitudinal section of a tool driver in accordance with my invention.

Fig. 2 is an enlarged central section of the handle end showing the spirally grooved spindle extended. Y y Fig. Sis a detail view ofthe operating cam sleeve.

Fig. 4 is a detail view of ythe indicator spring.

Fig. 5 is a transverse section on the line Fig. 6 is a view of the cam blank before it 1s rolled to form the operating cam sleeve shown in Fig. 3.

yconform to the hand. The handle has a central longitudinal bore therethrough, enlarged near the lower end of the handle by a counterbore. Set rigidly in the counter bore is the end of any operating cani sleeve 2 having a slightly reduced integral tubular extension 3 fitting the longitudinal bore of the han-dle. The upper end of the tube 3 is threaded vinternally as indicated to receive a cap screw 4 :fitting flush with the rounded end of the handle. The lower receive a shouldered cam cap' which seats on alocking cam socket 6. Thev cam socket 6 in addition to its locking functions serves as a bearing for a spindle 7 rotatably set up therein and extending up into the tube.

The spindle 7 has two cam grooves 8 and 9 which are developed in the form of oppositely pitched spirals intersecting each other at regular intervals. At it-s lower outer end, the spindle is keyed as indicated at 10 to receive the keyed end 11 of a tool 12'. In the embodiment shown, this tool is a screw driver blade.

Seated on the spindle 7 near its outer end and abutting the outer shoulder of the cam socket 6 is a grooved lock bushing 13, within which is removably held a split blade chuck 14. The chuck 141 is threaded between its ends as indicated to receive a knurled blade chuck nut 15. A covering sleeve 16 is driven over the forward portion of the bushing 13, covering the parts and providing a convenient grasping portion in the manipulation of the tool.

The inner end of the spindle 7 is tapped and threaded to receive a stop screw 17 between which and a stop washer 19 fitted to said end of the spindle a stop spring 18 is confined. Abutting the head ofV screw 17 and slidable in the tubular extension 3 is a plunger 20, between which and the cap screw l a powerful coil spring 21 is confined. The spring 21 is normally under compression, as shown in Fig. 1, but when released, expands and drives the spindle 7 outwardly with great force, as shown in Fig. 2, until the spindle is stopped by contact of the stop washer 19 with the thread 311 of the clutch piece 31. The purpose of the stop spring 18 is to cushion the shock produced when the outward movement of the spindle is stopped. With the spindle thus projected into extended position, the handle is reciprocated, and the reciprocatory movement is transmitted as rotary motion applied to the spindle by mechanism which will presently be described, the spring 21 holding the screw driver blade in the slot of the screw being driven in the ret-urn motion of the handle.

Rotatably mounted upon the fixed cam sleeve 2 is a controller sleeve 22, the interior of which is provided from end to end with a key way 25 engaged by spline-shaped projections on studs 26 and 27, which studs project through the slots 28 and 29 of the fixed cam sleeve 2. (Figs. 8 and 6). The slots 28 and 29 have their restricted ends projecting in opposite directions. The studs 26 and 27 engage respectively circumferential grooves 3()a and 31a of' the slidablc members 30 and 31 of crown ratchet clutches whose members 32 and 33 are fixed to the sleeve 2 by set screws 34. The members 30 and 31 have each a Aspiral thread 301 and 311 of a pitch corresponding to the pitch of the spiral grooves 3 and 9 of the spindle 7, and adapted to run each in one of said grooves. It will be apparent from this construction and the engaging relation of parts that a clock-wise movement of the controller sleeve 22 will move the stud 26 into the restricted end of the slot 28 and carry the slidable member 30 of the lower clutch out of engagement with the Xed member 32 of' said clutch while the upper spring 35 holds the slidable member 3l in engagement with the fixed member 33, the stud 27 being in the wide part of the cam slot 29. This produces ratchet motion in one direction. A turning of the sleeve in a counterclock-wise direction carries the stud 27 into the restricted end of the slot 29, disengages 31 from 33 and allows the ylower spring 25 to throw 30 into Vengagement with 32, causing a ratchet motion in the opposite direction. It will likewise be apparent that a medial position of the sleeve 22 and the studs 26 and 27 when both rest in the wide portions kof their respective slots 28 and 29 will allow both the slidable member 30 and 31, under the action of their respective springs 25, to engage thev fixed member 32 and 33 of the clutches and result in the locking of the spindle so that the tool will operate as an ordinary screw driver.

The upper end of the sleeve 22 has an indication which cooperates with suitable designations on the ferrule 11 of the handle to indicate the two directions of dri-ve and the neutral or solid position of the spindle. The lower end of the sleeve 22 has suitable designations which coperate with an indication on the outer face of the cam cap 5. The duplication of the related indications is simply for convenience of' reference by the user of the tool.

The sleeve 22 itself is locked in its central or neutral position by means of' a pai-r of' bowed springs 23 which are placed one on top of the other in a slot 21 formed in the fixed sleeve 2 (see Fig. 5) with their legs bearing against the ends of the slot, and their central portions disposed in position to enter the longitudinal groove or Vkeyway 25 formed in the rotatable sleeve 22, when said sleeve is turned into position to bring said key-way over said central portion of' the springs. This engagement is suflicient to lock the sleeve in its neutral or solid position against accidental turning movement, butl may be overcome by intentionally rotating the sleeve 22 to the right or left, in which case the springs 23 simply flatten out ,sufficiently to enable the sleeve to turn freely. The rotation of the sleeve 22 in either direction fromV its centraly or vneutral position is limited by the dogs 2,6 n and 27 reaching the restricted ends .of their cam slots y23 and 29 respectively. This prevents the sleeve 22 from being Vrotated through acomplete revolution.

The spindle is normally locked in thek position shown in 'F ig 1, wherein the spring 21 is underV compression, by a cam ring 36 rotatably mounted in the locking cam socket G. The cam ring 36 has two opposed double cam slots 37 in whicha pair of springV controlled locking studs 38 work. 4When the ring is rotated in one direction, its cam walls force the studs 38, against the-action- Y of a pair of circularly curved blade springs 39, into locking engagement with an annular groove 131 in the lock bushing 13. This locks the spindle rigidly to the handle so that it will turn only with the handle as in the case of an ordinary fixed screw driver.

'Where it is desired to use the tool as an ordinary ixed driver but with a long driver blade, as where a screw is located in a place diiricult of access, the spindle is unlocked by rotating the cam ring in the opposite direction from its direction of locking engagement. The spring 21 then projects the spindle and grooved lock bushing out into extended position. The spindle is then locked in this extended position or in any intermediate position by turning the controller sleeve 22 to neutral position. The spindle is returned to the position shown in F ig. 1 by rotating the controller sleeve 22 sufficiently to release the spindle whereupon it is pushed back into the handle to again compress the spring 21, and the cam ring is again rotated to engage the studs 38 in the groove 131 of the bushing, or the sleeve 22 may be turned to its neutral position, if desired. Either operation locks the spindle in its contained position within the handle. By this construction the proj ection of the spindle, by the spring 21 while the controller sleeve 22 is being adjusted, is prevented.

Various modifications in the form and construction of my device may obviously be resorted to within the limits of the appended claims.

What I therefore claim and desire to secure by Letters Patent is:

1. In a tool driver, a hollow reciprocable handle, a toolspindle carrying a tool and normally contained in said handle and adapted to be rotated thereby, a spring in said handle behind said spindle and normally under compression and expanding when released to project said spindle beyond said handle and adapted to hold the tool against an object being driven during the return motion of the handle, and a stop spring interposed between said spindle and said projecting spring and cushioning the shock when the spindle is projected by said projecting spring.

2. In a tool driver, a reciprocable handle having a boreclosedtat its lrearend, a tool spindle carrying a tool and rotatably mounted at the forward end of said. bore, ,and

adapted to be 'rotated by said handle, a headed plunger behind vsaid spindle and slidablein said bore of the handle,\aspring backing-said plunger and normally under compression 4and-expanding when released to project said spindle beyond said handle, and adapted yto hold the tool'against an object being driven on the return motion of the handle, a headed member carried by the rear end of said spindle with its head abutting the head of said plunger, and a stop spring confined between the head of said headed member and the rear end of the spine dle, and cushioning the shock when the spindle is projected by said projecting spring.

3. In a tool driver, a reciprocable hollow handle, a tool spindle rotatably mounted therein, mechanism for 'transmitting the reciprocatory motions of said handle as rotary motion applied to said spindle, a sleeve fixed over said spindle and having a slot, a rotatable governing sleeve covering said Vlixed sleeve for controlling the direction of rotation of the spindle, and provided with a recess, and a bowed sprin having its central portion disposed for loc ing engagement in said recess of the governing sleeve and its legs bearing against the ends of the slot in said fixed sleeve and adapted to yieldingly lock the governing sleeve against accidental rotation from a definite position when said' sleeve has been turned to bring its slot over the central locking portion of the spring.

4. In a tool driver, a reciprocable hollow handle, a tool spindle slidably and rotatably mounted therein, a spring in said handle behind said spindle normally under compression and expanding when released and projecting the spindle beyond said handle and adapted to hold said spindle against an object being driven upon the return motion of the handle, a locking mechanism for locking said spindle in either its normal con- Vtained position within the handle or in its projected position and for overning the direction of rotation thereo when in either position, and a supplemental locking mechanism operable independently of said firstnamed mechanism for locking said spindle in its contained position only and including a rotatable spindle engaging device carried by the handle and an engageable surface near the outer endof the-spindle.

5. In a tool of the class described, a handle having a longitudinal bore, a sleeve fixed in said bore, a spindle rotatable in said sleeve, a cam cap threaded into the outer end of said sleeve, a locking cam socket within said cap and constituting a bearing for the spindle,

said cam socket having a shouldered Seat and e tool holder held over the outer end of 10 for zn cani locking ring and having an open- Said spindle by seid bushinv. ing for a, looking piojeotion, a, cam looking In testimony whereof I affix-my signature n rotatable in said seat land khzvirlg a in presence o two Witnesses.

5 oo ing projection, a groove@ loo lus ing j,

, abutting said cam socket with its groove LARGY S' STARRElT" disposed opposite said locking projection, a Witnesses: covering sleeve driven over the outer end FRANK WING, of said' bushing and providing a hand hold, FLORENCE E. BOYGE.

Gopiespt this patentmay be obtained for ve centsach, by addressing the. Commissioner of Patenti,

Washington, D. C. 

